Public baby change areas may provide little counter space on which to lay out the items needed for changing the baby. In many instances, a change table is pulled down from a wall mounted unit and there may be no counter space at all.
A further problem is that there may be a hook to hang a diaper bag up on, but the diaper bag may have to be placed on a possibly dirty floor. In either case, the items needed for changing the baby would be in the diaper bag at arms length away from the caregiver.